Compound engine.



No. 725,935. PATENTED' APR, 21, 1903.

' E. M. CORYELL.

COMPOUND-ENGINE.

APPLIOATION FILED AUG. 20, 1901. no MODEL 2 SHEETS-SHEET 1L THE Nonms PETERS muono'ro-Lrrnoq wAsmNsroN, m c.

PATENTED APR. 21, 19 03. .E. M. OORYELL. COMPOUND ENGINE. APPLIUATION FILED AUG. 20, 1901.

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Wirlesses:

UNITED STATES PAT NT OFFICE.

EDWIN M. CORYELL, OF NEW YORK, Y., ASSIGNOR TO JULIA E. CAMERON, OF NEW YORK, N. Y.

COMPOUND ENGINE.

SPECIFICATION forming part of Letters ZEatent No. 725,935, dated April 21, 1903. Application filed August 20,1901. Serial No. 72,675. No modelpressure and low-pressure engines end to end,

so that their two pistons are in tandem upon a common piston-rod.

More particularly the invention consists,

further, in providing a single valve for the low-pressure engine thatis itself actuated by the pressure of steam from the high-pressure engine and that controls the admissionof steam to its own cylinder and also controls the final exhaust and another valve for the high-pressure engine that controls not only the admission of steam to its own cylinder and the discharge therefrom, but also the admission of such discharged steam to the lowpressure engine. Preferably the valve of the high-pressure engine is itself actuated by steam-pressure alone in the manner described in my Patent No. 688,598, granted December My invention consists, further, in certain details of construction to be pointed out.

one embodiment is illustrated. 7

In the drawings, Figure 1 isa longitudinal sectional view, the passage-ways connecting the high-pressure and low-pressure members being indicated by dotted lines. Fig. 2 is a plan view of Fig. 1. Fig. 3 is a transverse sectional view through line 111 Ill, and Fig. 4 is a similar view through line IV IV of Fig. 1-.

At the right hand of the figures is shown the primaryor main or high-pressure engine, and at the left the larger or secondary or lowpressure engine. They are arranged end to end. and united by the integral'casting X, while at Y Y are indicated arms for connecting the compound engine to a pump or the like. The two pistons B and N are in tandem and are fast on the common piston-rod ,0. :In the secondary is a single valve Q, ac-

tuated by the exhaust-steam from the primary,

- and inthe latter is a single valve preferably branches to ports 7 and 7 actuated by live steam and which itself serves to control both the inlet and the outlet of them ain cylinder as well as of the secondary cylinder and also the final exhaust, all as will be more particularly described.

In the primary or high-pressure engine A is the steam-cylinder, and B the main piston. C is the valve-chest, containing what I shall designate the spool-valve, that comprises the two piston-heads D D and the two flanges or belts D D, which define the three annular spaces d d d. At each end of the steamcylinder A is a tappet-valve E E, operated alternately. by the piston B. These valves E E control'the outlets l 1, leading from each end of the valve-chest, and they are normally held closed by the pressure of steam admitted through ports 2 2. Ports 3 and 3 lead from the valve-chestto the steam-cylinder, and ports 4 and '5 communicate with passages leading to the secondary or low-pressure engine. A port 6 leads through channel 6 to the final exhaust and is connected alternately (through space d) with ports 4 and 5.

C is the inlet-port for live steam, and it Small apertures (not shown) lead longitudinally through piston-heads D and D from spaces d and d, The inventionwill be best understood by z reference to the annexed drawings, in which respectively,

. The various parts of the spool-valve and the various ports are so arranged that when the spool is at one end of its chest (say the right end in Fig. 1) inlet 7 is cut off, inlet 7is open, annular space (1 affords communication from inlet 7' to inlet-ports 3 and 2, annular space (I affords communication between outlet-port 3 and port 4:, while annular space at connects port 5 with port 6. When the spool is at the other (left) end, these relations are reversed.

The operation of this high-pressure engine is substantially as in my said patent. In Fig. 1 the piston B has just completed its downstroke (tothe right) and has unseated tappet E, thus opening the outlet for passage 1 and exhausting the steam behind piston-head D. Thereupon the pressure on the other head, D, has immediately shifted the spool to the right, cutting off inlet-port 7, opening passage-way 7 d 2, and opening the communication 3 d 4 for the exhaust from the main or high-pressure cylinder, (behind piston B.) Steam is now admitted against valve E, tending to close it and start the main piston B on its back stroke, while the exhausbsteam passing out both relieves the opposing pressure on the rear of piston B and (operating in the low-pressure engine in a manner to be described) coacts with valve E in moving piston B back until the mouth of passage 3' is uncovered, when the live steam passes directly from inlet 0 through passage-way 7 cl" 3 into the steamcylinder behind piston B. The movement of the piston continues until it uuseats tappetvalve E at the other end of the stroke, when the proceedings are reversed. The pressure behind piston-head D is at once reduced and the spool immediately flies to the left, inlet 7 is out off, and inlet 7 opened and put into communication with port 2, (and 3 also,) while port 3 is put into communication with port 5 (through space d) and the piston B once more starts down to the right, and so on.

Referring now to the secondaryor low-pressure engine,M is the main steam-cylinder,and Nis the main piston on rod 0, common also to piston B. P is the valve-chest, in which the slide-valve Q is operated by the double-headed piston P P. Ports 21 and 21 lead from valvechest P to steam-cylinder M,each passage terminating in a (shallow) groove that extends very nearly to the adjacent head of the steamcylinder. A port 22 leads to the exhaust 23. The ports 21 and 21 and 2 2, the piston-heads P and P, and valve Q are all so arranged that in one position the space q beneath valve Q connects passage 21 with port 22, and in the other position the same valve-space q affords communication between passage 21 and port 22. From port 4 in the primary engine leads a passage-way 14, (indicated in Figs. 1 and 2 by heavy dotted lines,) that communicates with the adjacent end of valve-chest P, terminating in a groove 4: just clear of the face of piston-head P, and in like mannera passage-way 5 5 leads from port 5 in the primary engine into the farther end of valve-chest P, terminating in a'groove 5". (This passage is indicated in Fig. 1 by dots and dashes; see also Fig. 2.) Passages 24c and 24 lead, respectively, from the ends of valve-chest P into the valve-seat for alternate communication with valve-ports 21 and 21. The operation of this low-pressure member (considered apart from the primary engine) is also obvious. Steam from the exhaust of the primary engine is admitted by passage t and through the groove 4: into the valve-chest P behind piston-head P, which tends to slide valve Q to the left. At the same time the other end of the valve-chest has been cut off (in the primary) from its supply of steam and connected with the exhaust, so that the space at the left of pistonhead P being exhausted while steam is entering at the right the piston itself slides to the left, carrying valve Q with it. This uncovers ports 24 and 21 to admit steam behind main piston N, and the steam in front of the piston N is exhausted through port 21, space q, port- 22, and exhaust 23. Piston N is thus carried to the left until by the operation in the primary this action is reversed, steam then coming in at 5 24 21 and exhaustingfrom the other end of the cylinder through passage-way 21 q 22 23.

The operation of my compound engine as a whole may now be clearly set forth. The main piston B has just unseated tappet-valve E and exhausted behind pistonhead D, which last has just passed to the right. The fresh steam under high pressure enters at C through 7 d 2 and tends to push piston B to the left, (by means of valve E.) The exhaust-steam from the main steam-cylinder passes out through 3 d 4.- 4: 1" and tends to push secondary valve Q to the left, thesteam behind this secondary piston head being now free to exhaust through 5 5 5 d 6 6 23, whereby the secondary valve Q is moved to the left. passes through ports 24 21 behind secondary piston N and starts the latter to the left. By this time the main piston B has uncovered port 3 and is itself being propelled to the left by steam from C 7 d 3. The exhaust from the secondary is through 21 q 22 23. At the end of the stroke of the pistons piston B unscats the tappet-valve at E, main valve D is shifted to the left, steam begins to push against tappet E and then against piston B, the exhaust behind piston B passes through 3 d 5 5 5 into the farther lefthand end of chest P, secondary valve Q is shifted back to the right, and steam is admitted to the left of secondary piston N, while its exhaust is through 21 q 22 23, all this being just the reverse of the former operation, and so on continuously.

It will be noted that the secondary valvechest, except for the exhaust, has all its communications leading back to the primary, so that no packings or bearings, &c., are called for; that only a single valve is found in the secondary; that the single valve in the primary acts not only as the main valve for its high-pressure cylinder, but as well controls the admission into the secondary of steam discharged from the primary and also controls the final exhaust, and that the two pistons work simultaneously with a single piston-rod.

I do not limit myself to the exact arrangement described and shown, since changes may be made in the construction without departing from the spirit of my invention.

Having thus fully described my invention and the best mode in which I contemplate carrying it out, I claim 1. In a compound steam-engine, the combination with a high-pressure cylinder and its valve-chamber communicating therewith by two ports, a low-pressure cylinder and its The steam from 3 4 4 4: then valve-chamber communicating therewith byv two ports, two passage-ways leading between said valve-chambers, and an exhaust-channel leading to each valve-chamber, of a valve in said low pressure valve-chamber actuated through said passage-ways and controlling its two ports aforesaid "and said exhaust, and 'a' valve in said highpressure valve chamber that controls its two'ports aforesaid and also said two passage-waysas well ,as said exhaust.

2. In a compound engine, the combination bf a high-pressure cylinder and a low-pressure cylinder arranged end to end, a valvechest and valve for each, and suitable ports and passages between said valve-chests and cylinders controlled by said two valves, with a piston in each cylinder, the 'twopistons being fast on aicommon pistons-rod, but there being no mechanical connection between said valves. V

3. In a compound engine, the high-pressure. engine comprising asteam cylinder and its piston, a valve-chest'connected with said cylinder by two ports, and a spool-valve in said chest operated by steam-pressure which is controlled by tappet-valves actuated .by said piston, in combination with two passage 'ways and an exhaust-channel which lead from said valve-chest to the secondary engine and which are so arranged relatively with said spool-valve that one of said ports and one of 'said'passage-ways are put into communication while simultaneously the other port is in communication with said 'exhaust-channel. I I

4. In a compound engine, the low-pressure' engine comprising'a steam-cylinderand a valve-chest connected by two ports, two passage-ways leadingvfrom the high-pressure engine to said chest, and an exhaust-channelv leading from said valve-chest, in combinaam with a valve in said chest that connects each of said ports alternately with said ex! haustchannel, a double-headed piston carrying said valve and actuated alternately through each of said passage-ways, and means in the high-pressure engine for controlling said passage-ways.

5. In a compound engine, the combination with the high-pressure member consisting of the valve-chest with its valve and the'steamcylinder with its piston, and the low pressure member consisting of its valve-chest withits valve andits steam-cylinder with its piston, of two passage-ways leading respectively from said high-pressure valverchest to the opposite ends of said low-pressure valve chest, the inlet of steam from said high-pressure steam-cylinder into said passage-ways alternately being controlled by said highpressure valve, and the steam in said passage-ways alternately shifting said low-pressure valve and subsequently said low-pres sure piston,'the other passage-way acting'in turn as theexhaust for said low-pressure member, substantially as described.

specification in the presence of ing witnesses.

{EDWIN M. OORYELL.

two subscr-ib- Witnesses:

' C. A. L. MASSIE,

'ELIsHA K. CAMP.

In testimony whereofI have signed this I 

